The Mass Spectrometry facility is active in enhancing the capabilities of the Micromass ZAB-T four-sector mass spectrometer. One of the options is using MALDI as an ionization method. Since the ZAB-T is equipped with an extended array detector, we have built a unique MALDI probe which we may use in the MS mode, using the back source of the instrument, or in a MS/MS mode, using the front source. We propose to explore the MALDl ionization method on a sector instrument to determine sensitivity and resolution capabilities. We plan to use this source for MS/MS analysis of immunological related peptides, carcinogen modified-DNA and complex lipids.